This application is based on Japanese Patent Application Nos. 2000-102734 filed Apr. 4, 2000 and 2001-030166 filed Feb. 6, 2001, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a moving up and down apparatus of a print head for vertically moving the print head, and to a printing apparatus incorporating same.
2. Description of Prior Art
An ink-jet printing apparatus, in general, may be provided with a moving up and down apparatus for moving up and down a print head provided in the printing system thereof relative to a recording surface of a printing medium or to a capping member or the like of a recovery processing unit for performing recovery processing of print head is used in practical application.
Such a moving up and down apparatus, for example, comprises a print head support member for supporting the print head for ejecting an ink onto the recording surface of the printing medium for performing printing operation, a drive mechanism for vertically moving the support member relative to the recording surface of the printing medium or the capping member or the like of the recovery processing unit, and a drive motor.
The drive mechanism is to move up and down the print head support member relative to the recording surface of the printing medium or the capping member or the like of the recovery processing unit according to a drive force from the drive motor transmitted through a speed reducer having a predetermined reduction ratio. The drive mechanism moves up and down the print head support member, for example, by a screw movement.
For example, when the print head is a so-called continuous length type having a relatively large number of ink ejection openings, since a total weight of the above print head support member and the print head is relatively large, when a drive motor of relatively low power is used, it is necessary to set the reduction ratio of the speed reducer to a relatively large value. However, when the reduction ratio of the speed reducer is set to a relatively large value, since the vertical moving speed of the print head support member is decreased, there is a limit in utilizing a drive motor of relatively low power.
Further, in the above drive mechanism, because there is play, that is, a backlash, between mechanical elements, for example, between a screw shaft and a screw hole for performing screw movement, when the capping and blade and the like of the recovery processing unit come in contact with the ink ejection part of the print head at a predetermined pressure, the print head support member and the print head are pressed and moved by a moving distance corresponding to the backlash, therefore, there is a fear that capping and wiping will not be performed sufficiently accurately.
In view of the above problems, an object of the present invention is to provide a moving up and down apparatus of a print head, and printing apparatus capable of removing a backlash between component elements of the moving up and down mechanism, removing a backlash between component elements of the moving up and down mechanism by a constant urging force, and capable of providing a downsizing of the drive motor.
In accordance with the present invention which attains the above object, there is provided a moving up and down apparatus of a print head comprising a print head support part for supporting the print head which performs an ejection of a liquid in order to perform a printing operation of printing on a recording surface of a printing medium, a drive force transmitted part provided in the print head support part to receive and transmit a drive force for reciprocally moving the print head support part, a drive force transmission part engaged with the drive force transmitted part through a gear teeth part for transmitting the drive force to the drive force transmitted part, a drive force supply part connected to the drive force transmission part for supplying the drive force to the drive force transmission part, and an urging member for urging the print head support part in a predetermined direction.
Further, the moving up and down apparatus of print head according to the present invention comprises a print head support part for supporting a print head for performing a printing operation of printing on a recording surface of a printing medium, a screw shaft member provided on said print head support part in which a first screw part is formed along a moving direction of the print head support part, a drive force transmission member provided in the print head support part having a first screw part formed along a moving direction of the print head support part and a second screw part engaged. with the first screw part of the screw shaft member for transmitting a supplied drive force to the screw shaft, a drive force supply part connected to the drive force transmission member for supplying a drive force, and an urging member for directly or indirectly urging the screw shaft member or the drive force transmission member in a direction.
Yet further, the printing apparatus according to the present invention comprises a print head for ejecting a liquid in order to perform a printing operation of printing on a recording surface of a printing medium, a print head support part for supporting the print head, a drive force transmitted part provided in the print head support part to receive and transmit a drive force for reciprocally moving the print head support part by a predetermined distance, a drive force transmission part engaged with the drive force transmitted part through a gear teeth part for transmitting the supplied drive force, a drive force supply part connected to the drive force transmission part for supplying a drive force, and an urging member for urging the print head support part in a predetermined direction.
As can be seen from the above description, with the moving up and down apparatus of the print head, and the printing apparatus, according to the present invention, since the urging member urges the print head support part in a predetermined direction, backlash between component elements of the vertical moving mechanism can be removed, and the drive motor be downsized.
Further, since the urging member urges the screw shaft member or the drive force transmission member in a predetermined direction, directly or indirectly, backlash between component elements of the vertical moving mechanism can be removed by a constant urging force irrespective of the vertical moving position of the print head.
The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.